Air Balancing: 15 Ways to Avoid Hot and Cold Spots (Updated)

September 2, 2023

Air balancing will improve air circulation, increase energy efficiency and enhance the overall performance of your air conditioning and heating system. For a homeowner, it means delivering the right amount of air (hot or cold) to each room making your home more comfortable.

Air balancing for a HVAC technician is the process of testing and adjusting your system using their skill and tools of the trade. They look at your intake and output and adjust accordingly.

Rob Falke, President, National Comfort Institute -- an HVAC-based training company, adds "balancing is the single-most important step that can be taken to assure your systems produce comfort and operate efficiently." 

In this article, I'll share ways you can do-it-yourself to adjust (balance) your airflow for comfort. A comfort balance is as simple as checking whether a room feels comfortably conditioned. Then, I'll share ways that may require a HVAC professional and I'll help you understand how a technician will go about actually balancing a residential system. This may require installing dampers or moving registers.

 

Bonus Offer: Free Air Filter Replacement Reminder. Never forget to replace your air filter again, with a notification sent to your inbox when it's time to replace your filter!

 

What is Air Balancing?

Air balancing is the process that involves modifying your existing HVAC system to make sure that air is evenly distributed throughout the home. All zones will have the correct amount of heat transfer. You want all components of your HVAC system working in harmony.

15 Tips on Balancing the Temperatures in Your Home 

It's time to avoid those pesky hot and cold spots and uneven temperatures.  I broke it down into easy, do-it-yourself tips, to harder may need some skill, to it's time to contact a professional.

  1. Close or Open Your Register
  2. Try a 2 Degree Offset
  3. Check Filters for Cleanliness
  4. Install Window Coverings to Prevent Heat
  5. Avoid Placing Electronic Equipment Near Thermostat
  6. Check for Drafts
  7. Adjust Ceiling Fans
  8. Prevent Airflow Restrictions
  9. Place Thermostat Fan Setting to "ON"
  10. Fix Your Duct Work
  11. Check Your Insulation
  12. Check and Adjust the System's Blower Fan Speed
  13. Install Extra Return Ducts if Necessary
  14. Use Two Air Handlers
  15. Know the Size of Your HVAC System

 

Do it yourself...

1. Close or Open Your Register

Simple yet effective. You have the ability to move the damper blade. It will restrict air flow in the room. But, don't completely close the vents, it could cause other issues to your HVAC system.

During warm weather temperatures, open registers on your upper floor and partially close registers on first floor and / or your basement. During cold temperatures, reverse the process.

Sierra Air Conditioning put together a handy guide to get your system properly balanced for each season. Try this process first:

Step 1: Set your thermostat to 76-78 degrees. (ideal range to start testing)

Step 2: Leave the temperature alone for at least 24 hours.

Step 3: In areas that are too cool, adjust the vents to allow for less air flow. 

Step 4: Adjust in small increments to feel what works for your comfort.

Step 5: Re-check your adjustments (24 hours later) to feel if you reached the desired temperature.

Step 6: Continue until you reach your ideal temperature.

2. Try a 2 Degree Offset

If you're in a two-story home and have two thermostats, set the temperatures to have a 2 degree off-set.

Here's what I mean...

Set the thermostat at a 2 degree difference for the floors. For example, upstairs could be set at 74 degrees and downstairs at 72. This will help with uneven temperatures. 

3. Check Filters for Cleanliness

 There are numerous reasons to keep your filters clean...

  • Improves your air quality - cleaning the debris that builds up on your filters will aid with the flow of air.
  • Increases the efficiency of your furnace - reduced air flow through your heating and cooling system can cause your heat exchange to overheat and shut off too quickly. Keep the filter clean and it will aid in the efficiency of your furnace.
  • Extend the life of your HVAC system - would you believe the most common reason a HVAC breaks down is due to a dirty filter? A dirty filter makes your system work harder causing it to overheat.
  • Help keep energy costs down - Heating your home uses more energy and costs more money than any other system in your home -- typically making up about 42% of your utility bill. If your filter is not clogged your system will run more efficient. This alone will help keep your energy costs down. When you regularly change your filter, you can save from 5 to 15% on your bills.

4. Install Window Coverings to Prevent Heat

Your windows will impact the comfort level in each room. Windows without drapes, blinds, shades etc. can heat up a room faster before a thermostat has the time to turn on and add relief.

Window coverings can make a difference in the overall appeal and comfort level. They also can help improve energy efficiency. In cooling seasons, about 76% of sunlight that falls on standard double-pane windows enters to become heat.

5. Avoid Placing Electronic Equipment Near Thermostat

Electronic equipment creates a lot of heat and can really affect your comfort. Nowadays with the addition of large screen TV’s and computers, the distribution of heat in the room can change and may require adjustments to your vents.

This is typically noticed if you have a room air conditioner. The thermostat can pick up heat from appliances which can also cause your A/C to operate longer.

6. Check for Drafts 

You want to make sure your windows and doors are sealed properly as these often cause cold spots in your home. 

7. Adjust Ceiling Fans

Changing the directional settings of a fan can have a profound effect on air circulation. Your ceiling fans should go counterclockwise during warming months to create cool downward airflow. However, it should go at a low speed in a clockwise motion during the cooler months so it can help evenly distribute warm air.

8. Prevent Airflow Restrictions

Do not cover registers with furniture or items that will restrict air flow. When you block a vent with furniture your system has to work harder. Vents are there to supply free flow of air.

Here's a quick fix from Integrity Air:

"Your vents need 18 inches of space. Rearrange your furniture and hem your curtains so you can provide them with the air flow they need. If you have no other choice, get a magnetic air deflector so that the air blows away from the nearby furniture."

Deflectors can redirect the air flow keeping the intended air circulation.

9. Place Thermostat Fan Setting to "ON"

Your fan setting can have an impact on your indoor air quality and comfort level. Most systems have two fan settings: On and Auto.

By utilizing the "ON" setting, the fan will blow continuously which will filter and always be replacing your indoor air. This in turn, will keep the air steady. In using the auto position, your air can become more stagnant.

Both come with pros and cons. When flipping to the On setting, you may see an increase in your utility bill. 

Bonus Do-it-Yourself tips...

Watch as Dave Mars, Columbia Water & Light describes the importance of balanced air flow in a heating and cooling system.

Making sure your vents are working properly and preventing leaks in ducts will help save money and energy.

Another step-by-step guide, How to Balance Your Central Heating System, lists the steps needed to take in the cooling and heating season.  

Resource: How to Balance Your Central Heating System

https://www.dummies.com/home-garden/interiors/ventilation/how-to-balance-your-central-heating-system/

 

Next up: Not so do-it yourself air balancing tips...

10. Fix Your Duct Work

Fix any duct work damage and or defects. Problems with the duct work can cause uneven distribution. 

If the duct air flow system is out of balance you will find that when heating, some rooms are not warm enough while others are too cool. While in air conditioning mode, you'll find similarly that some rooms are not cool enough while others are too warm.

Depending on your skill you could:

  • fix loose duct joints by refitting and sealing the junction.
  • look for ductwork with sharp turns
  • insulate or seal the ducts

Always best to contact a HVAC professional.

11. Check Your Insulation

If you think your home isn’t properly insulated, or you think you may not have insulation, hire a professional to do an evaluation. They will help find any problems with your insulation. 

12. Check and Adjust the System's Blower Fan Speed

Switching the fan speed can be easy if you know what you are doing. 

Hunker gives a step by step tutorial, "How to change air handler fan speed" from disconnecting the power to testing the unit.

The steps include...

  • disconnecting the power
  • locating the blower motor and wiring
  • identifying the speed wires
  • changing the active speed wire
  • testing your HVAC system

13. Install Extra Return Ducts if Necessary

"A second return duct can lower static pressure if the airflow bottleneck is on the return side." 

Blake Shurtz, Greiner wrote an informative article on Adding a Second Return is Almost Always a Good Idea.

14. Use Two Air Handlers

"If a single air handler is used for both heating and cooling, a basement located air handler will have an easier time pushing warm air up into higher floors of the home than it will pushing cool air up into the same spaces during the cooling season.

(Warm air rises through a building by convection while heavier cool air tends to fall).

Increased fan speed for cooling operation or booster fans may help. To avoid this problem some HVAC designs use two air handlers, placing the second unit in the attic or ceiling above the uppermost floor."  [source

15. Know the Size of Your HVAC System

Make sure the size of your HVAC system correlates with the size of your home. You don’t want a unit that is too small and you don’t want one that is too large because it will over condition your home. When the furnace is too large, it can cause some issues in the home. From short cycling to inefficient operation to an uncomfortable living space.

Sizing a furnace accurately is really the job of a qualified HVAC contractor. To recommend the right furnace size, the professional should perform a whole house evaluation.

What Air Balancing Can Do For You Today

Efficiency

  • Improve air circulation
  • Less conditioned air escapes
  • Lower energy bills because unbalanced air systems cause stress and overwork
  • Optimized system performance - increase energy efficiency
  • Longer lifespan for HVAC equipment

Better Indoor Air Quality

  • When circulation is bad contaminants become present
  • Food/health safety issues are involved with contaminated air
  • Healthier environment
  • Equalized pressure
  • Prevents dirt/dust/mold from clogging systems

Improved Comfort

  • Getting rid of cold/hot spots will lead to overall greater comfot
  • For commercial facilities, it will lead to improved satisfaction which equals better productivity
  • Humidity control

Air balancing is a method of testing your heating and cooling system to spot any problems that are causing uneven airflow or negative air pressure. By doing this, every room in your home will be as comfortable as possible with the equipment you have.

Balancing your central heating minimizes energy consumption and evens temperatures in each room.

To check the air balance, HVAC technicians will need to test your system's performance. 

What a Professional Technician Will Do 

 "Find the tonnage or heating output to determine required system airflow. Divide the total system airflow so each room has its share. This can be done using Manual J or one of several estimating techniques, including calculating air changes."

That's just the start at where a HVAC expert will begin.

Here's a great article on How to Balance a Residential HVAC System. Rob Falke goes over action steps to balancing a system:

  • gather the design information
  • inspect and start up the system
  • take initial airflow readings
  • compare design to actual airflows

An air technician runs diagnostic tests on your ductwork and other systems. They run a TAB - testing, adjusting and balancing.

What are some tools that are involved?

  1. static pressure readings with a manometer
  2. measuring the output of conditioned air from supply registers with a flow hood
  3. hygrometer used for checking temperature, humidity, and heat gains and losses 

Extra Resource: Case Study: the Jones family, the process, challenges, and benefits.

Residential Airflow Balancing: Why it Matters in Creating More Comfortable Homes. https://www.achrnews.com/articles/139940-residential-air-flow-balancing-why-it-matters-in-creating-more-comfortable-homes

Conclusion

When in doubt, the best recommendation is getting a professional opinion from a HVAC technician

Some of the air flow tips are easy and can be done today.

Which tip are you going to try first?

- check your filter for cleanliness?

- move your furniture or buy a air deflector?

Live in Northeast Ohio? Get an Estimate
If you're having problems with your HVAC system we'd love to help, Schedule an Appointment or Get Estimate to talk to an HVAC professional today
Schedule Service Today!